During half-duplex communications between two nodes, one node transmits data and the second node, upon receiving the data, sends an acknowledgment signal indicating that the second node properly received the data. When the second node has data to transmit, it transmits the data to the first node and the first node, upon receiving this data from the second node, sends an acknowledgment signal indicating that the first node properly received the data. While the first node is sending data to the second node, or the second node is sending data to the first node, other communications are limited. No simultaneous transmission and reception in a single frequency bin (a specific time interval associated with a specific frequency band) occur. This back-and-forth pattern of communication, known as half-duplex, is inefficient in comparison to full-duplex communications, where both nodes can simultaneously transmit and receive data in a single frequency band or channel at a given time.
However, the efficiency of full-duplex communications is reduced when, after transmitting data, a transmitting node waits a significant amount of time for the receiving node to send an acknowledgment that the data was received. In full-duplex communication, the receiving node may simultaneously be transmitting a frame and thus must wait until its transmission is complete before sending an acknowledgment for the frame it received. Acknowledgments also aid in knowing if data was corrupted or otherwise not properly received, necessitating retransmission of the data.